      DOUBLE PRECISION FUNCTION X02AAF(X)
C     MARK 12 RE-ISSUE. NAG COPYRIGHT 1986.
C
C     RETURNS  (1/2)*B**(1-P)  IF ROUNDS IS .TRUE.
C     RETURNS  B**(1-P)  OTHERWISE
C     I.E. RETURNS THE SAME VALUE AS X02AJF
C
C     .. Scalar Arguments ..
      DOUBLE PRECISION          X
C     .. External Functions ..
      DOUBLE PRECISION          X02AJF
      EXTERNAL                  X02AJF
C     .. Executable Statements ..
      X02AAF = X02AJF()
      RETURN
      END
